On Sat, Jun 22, 2013 at 05:59:05PM -0400, Dave Jones wrote: > On Sat, Jun 22, 2013 at 07:31:29PM +0200, Oleg Nesterov wrote: > > > > [ 7485.261299] WARNING: at include/linux/nsproxy.h:63 > get_proc_task_net+0x1c8/0x1d0() > > > [ 7485.262021] Modules linked in: 8021q garp stp tun fuse rfcomm bnep > hidp snd_seq_dummy nfnetlink scsi_transport_iscsi can_bcm ipt_ULOG can_raw > rds af_802154 nfc can rose caif_socket caif llc2 af_rxrpc phonet ipx p8023 > p8022 pppoe pppox ppp_generic netrom slhc ax25 x25 af_key appletalk atm psnap > llc irda crc_ccitt bluetooth rfkill coretemp hwmon kvm_intel > snd_hda_codec_realtek kvm snd_hda_codec_hdmi crc32c_intel ghash_clmulni_intel > microcode snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device pcspkr > snd_pcm snd_page_alloc e1000e snd_timer ptp snd pps_core soundcore xfs > libcrc32c > > > [ 7485.265434] CPU: 2 PID: 5623 Comm: trinity-child3 Not tainted > 3.10.0-rc6+ #28 > > > [ 7485.267158] ffffffff81a1529c ffff8801c8eafd30 ffffffff816e432d > ffff8801c8eafd68 > > > [ 7485.268045] ffffffff8104a0c1 0000000000000000 ffff880225e9bd18 > ffff8801bc6e4de0 > > > [ 7485.268932] 0000000000000000 00000000000000dd ffff8801c8eafd78 > ffffffff8104a19a > > > [ 7485.270463] Call Trace: > > > [ 7485.271338] [<ffffffff816e432d>] dump_stack+0x19/0x1b > > > [ 7485.272207] [<ffffffff8104a0c1>] warn_slowpath_common+0x61/0x80 > > > [ 7485.273092] [<ffffffff8104a19a>] warn_slowpath_null+0x1a/0x20 > > > [ 7485.273942] [<ffffffff81229f58>] get_proc_task_net+0x1c8/0x1d0 > > > [ 7485.274793] [<ffffffff81229d95>] ? get_proc_task_net+0x5/0x1d0 > > > [ 7485.275659] [<ffffffff8122a0bd>] proc_tgid_net_lookup+0x1d/0x80 > > > [ 7485.276531] [<ffffffff811b778d>] lookup_real+0x1d/0x50 > > > [ 7485.277646] [<ffffffff811b7d83>] __lookup_hash+0x33/0x40 > > > [ 7485.278477] [<ffffffff811bb143>] kern_path_create+0xb3/0x190 > > > [ 7485.279345] [<ffffffff811b93d5>] ? getname_flags+0xb5/0x190 > > > [ 7485.280292] [<ffffffff811bb261>] user_path_create+0x41/0x60 > > > [ 7485.281233] [<ffffffff811be6bb>] SyS_symlinkat+0x4b/0xd0 > > > [ 7485.282072] [<ffffffff816f5a54>] tracesys+0xdd/0xe2 > > > [ 7485.282973] ---[ end trace 2204b7c65d6c5519 ]--- > > > > Hmm. The test case tries to create the symlink in /proc/*/net/ ? > > hit it with symlink, but also some other syscalls. eg: > > WARNING: at include/linux/nsproxy.h:63 get_proc_task_net+0x1c8/0x1d0() > Modules linked in: 8021q garp stp tun fuse rfcomm bnep hidp snd_seq_dummy > nfnetlink scsi_transport_iscsi can_bcm ipt_ULOG can_raw rds af_802154 nfc can > rose caif_socket caif llc2 af_rxrpc phonet ipx p8023 p8022 pppoe pppox > ppp_generic netrom slhc ax25 x25 af_key appletalk atm psnap llc irda > crc_ccitt bluetooth rfkill coretemp hwmon kvm_intel snd_hda_codec_realtek kvm > snd_hda_codec_hdmi crc32c_intel ghash_clmulni_intel microcode snd_hda_intel > snd_hda_codec snd_hwdep snd_seq snd_seq_device pcspkr snd_pcm snd_page_alloc > e1000e snd_timer ptp snd pps_core soundcore xfs libcrc32c > CPU: 2 PID: 12821 Comm: trinity-child2 Tainted: G W 3.10.0-rc6+ #28 > ffffffff81a1529c ffff8801bcbdbc70 ffffffff816e432d ffff8801bcbdbca8 > ffffffff8104a0c1 0000000000000000 ffff880226704828 ffff8801b95a7090 > 00000000ffffff9c 0000000000000008 ffff8801bcbdbcb8 ffffffff8104a19a > Call Trace: > [<ffffffff816e432d>] dump_stack+0x19/0x1b > [<ffffffff8104a0c1>] warn_slowpath_common+0x61/0x80 > [<ffffffff8104a19a>] warn_slowpath_null+0x1a/0x20 > [<ffffffff81229f58>] get_proc_task_net+0x1c8/0x1d0 > [<ffffffff81229d95>] ? get_proc_task_net+0x5/0x1d0 > [<ffffffff8122a0bd>] proc_tgid_net_lookup+0x1d/0x80 > [<ffffffff811b778d>] lookup_real+0x1d/0x50 > [<ffffffff811b7d83>] __lookup_hash+0x33/0x40 > [<ffffffff816e3635>] lookup_slow+0x44/0xa9 > [<ffffffff811bae88>] path_lookupat+0x7b8/0x810 > [<ffffffff8119d3d2>] ? kmem_cache_alloc+0x142/0x320 > [<ffffffff811b936f>] ? getname_flags+0x4f/0x190 > [<ffffffff811b936f>] ? getname_flags+0x4f/0x190 > [<ffffffff811baf0b>] filename_lookup+0x2b/0xc0 > [<ffffffff811be144>] user_path_at_empty+0x54/0x90 > [<ffffffff81145965>] ? user_exit+0x45/0x90 > [<ffffffff810b773d>] ? trace_hardirqs_on_caller+0xfd/0x1c0 > [<ffffffff811be191>] user_path_at+0x11/0x20 > [<ffffffff811d5338>] SyS_lgetxattr+0x38/0x90 > [<ffffffff816f5a54>] tracesys+0xdd/0xe2 > ---[ end trace 2204b7c65d6c551a ]--- > > > and a bunch of other similar VFS related calls.
All these VFS related calls try to work with /proc/PID/ns/SMTH. If a process is zombie, it's detached from namespaces (except pidns), so if we try to read /proc/PID/ns/SMTH, we get this warning. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
